This paper presents a detailed description of an advanced Adaptive Cruise Control (ACC) system implemented on a Renault-Volvo Trucks vehicle. One of the main differences between this new system, which is called the Smart Distance Keeping (SDK), and the classical ACC is the choice of the safe distance. This later is the distance between the vehicle (with the ACC or the SDK system) and the front obstacle (which may be a vehicle). It is supposed fix in the case of the ACC, while variable in the case of the SDK. The variation of this distance (in the case of SDK) depends essentially on the relative velocity between the vehicle and the front obstacle. The choice of this distance influences the velocity regulation. The main contribution of this work is on the SDK system architecture, the design of its environment model, and the proposition of a detection and isolation strategy for some of the possible faults that may be produced on the system.

No abstract

Content-addressable memories (CAMs) enable the comparison of their entire content to a search word in one single access. Ternary CAMs (TCAMs) provide the possibility to store and handle not only 0 s and 1 s but also don't cares. A way to protect TCAMs implemented with static random-access memory (SRAM) cells against soft-errors is proposed. Asymmetric SRAM cells are used to reduce the probability that soft-errors (a) affect don't cares and (b) corrupt 0 s and 1 s into anything else than a don't care. This implies that soft-errors will only have the tendency to generate false-hits that point to an erroneous matching word. Such a failure can be mitigated with the help of an error-correcting code (ECC), as is the case with conventional memories. Other types of failures which are more difficult to detect and locate, i.e. false-misses or false-hits that point to an error-free matching word or false-misses, become very rare or non-existent.Introduction: Content-addressable memories (CAMs) are special memories with high-speed parallel-search capability. Ternary CAMs (TCAMs) enable the storage and comparison of don't cares besides 0 s and 1 s, the property that can be used to reduce storage requirements. TCAMs are especially used in network routers to provide next-hop information or packet classification for flexible quality-of-service policies [1].Static random-access memory (SRAM) is still the prevailing storage infrastructure in TCAMs, despite the existence of other technologies [2][3][4]. Unfortunately, the SRAM cells are vulnerable to soft-errors [5]. During a lookup operation in a TCAM, the presence of soft-errors may induce a false-hit, i.e. an incorrect address is returned, or a falsemiss, i.e. no address location is returned despite the fact that a word compatible with the search word was stored in the TCAM.Several schemes have been proposed to offer protection against softerrors in SRAM-based TCAMs. Circuit-level solutions presented in [6] are able to reinforce 1 and 0 values stored in the TCAM cells but don't care values are left unprotected. At architectural level, false-misses can be detected with the help of special redundant structures called Bloom filters [7]. Nevertheless, false-hit detection with Bloom filters is not guaranteed and false-miss detection is pessimistic in the sense that truemisses can get mixed-up with false-misses. In CAMs error-correcting codes (ECCs) can be applied only during scrubbing campaigns [8] due to the parallel nature of the search operations. The inherent limitation of such an approach is that soft-errors are not treated until the first scrubbing campaign following their occurrence.In this Letter, a solution is proposed to improve the ECC-based protection of SRAM-based TCAMs against soft-errors. This solution is inspired by the following observations: